Human Impact on the Environment (WJEC GCSE Biology)
Revision Note
Conflict between Human Need & Conservation
A rapidly increasing human population means that the human need for resources continues to increase, e.g.
More agriculture is needed to ensure that enough food is produced
Land requirements for housing are increasing
Industry requires more land and energy and also produces more pollution
The increased need for resources means that human requirements are often in conflict with the needs of other species
Environmental impact assessments
Proposed developments, e.g. housing or industrial buildings, can only go ahead once an environmental impact assessment has been completed
During an environmental impact assessment, biologists study the proposed development site to identify local species and determine the value of the site to wildlife
Endangered or protected species might be found, e.g. great crested newts
Important sites, such as maternity bat roosts, might be present
The assessment will determine the effects of a particular development on local wildlife and will put forward solutions to reduce its impact
The findings of an assessment may mean that:
Developers need to modify their plans to protect certain endangered species, e.g. relocating newts to another local pond
Developers are granted permission under certain conditions, e.g. they may be asked to plant more trees, or build new habitats for displaced species
Permission may be refused if environmental damage cannot be mitigated
Bouke ten Cate, CC BY-SA 4.0, via Wikimedia Commons
An environmental impact assessment may be carried out to determine whether great crested newts are present on a proposed development site; if they are found then developers would be expected to protect them
Government agencies
In addition to environmental impact assessments, which are often carried out by biologists working for private companies, there are government agencies tasked with reducing the impact of human activities on the environment, e.g.
The Environment Agency
Involved with ensuring that development is carried out in a sustainable way
Has responsibility for waste management
Intensive Farming Methods
In order to produce enough food to feed a growing human population, some farmers are turning to more intensive farming methods
Intensive farming aims to produce more food with reduced energy and land inputs
Advantages and disadvantages of intensive farming table
Farming method | Advantages | Disadvantages |
|---|---|---|
Agricultural machinery | Allows farmers to farm larger areas of land easily Machinery can monitor crop health more effectively, reducing losses to disease and ensuring that harvesting is carried out at the correct time; this results in increased yields | May take jobs away from people Machinery usually runs on fossil fuels Smaller fields may need to be combined into larger fields, resulting in losses of hedgerow habitats |
Chemical fertilisers | Increases soil nutrient availability, leading to larger crop yields | Fertilisers can run off into local bodies of water, leading to eutrophication |
Insecticides and herbicides | Kills insect pests and reduces competition from weeds, leading to larger crop yields | May kill non-target species May lead to the evolution of pesticide and herbicide resistance |
Selective breeding of crop and animal species | Can be used to produce food varieties that are resistant to environmental damage, have a higher yield, and taste better | Such varieties are often grown as monocultures, reducing biodiversity Selectively bred varieties may have low genetic variation, reducing their ability to adapt to change |
Disease control | Antibiotics may be used to prevent disease in livestock populations; this reduces losses due to disease and leads to increased meat production | Overuse of antibiotics can increase the likelihood of antibiotic-resistant strains emerging Antibiotics may be present in meat |
Battery farming of livestock | Livestock live in small, temperature controlled spaces, reducing energy losses due to movement and temperature regulation; this means that more energy is used in growth and meat production increases | Many have concerns about the welfare of animals farmed in this way Disease can spread easily, leading to the loss of many animals at the same time; this can be expensive for farmers |
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